A door for wooden furniture is usually assembled and connected to the furniture using hinges, so as to be opened and closed relative to the furniture. FIGS. 1 and 2 are assembled and partially exploded perspective views, respectively, of a conventional door hinge 10, which includes a first fixing member 11 for fixing to a door 18, a second fixing member 12 for fixing to a wall surface of a storage space, such as a cabinet, an adjusting member 13 mounted on the second fixing member 12, a turning member 14 for pivotally connecting the adjusting member 13 to the first fixing member 11, a spring leaf 15, and a torsion spring 16. The adjusting member 13 is held to the second fixing member 12 with a first screw 17. The turning member 14 is pivotally connected at a first end to the first fixing member 11 and at a second end to the adjusting member 13. With the spring leaf 15, the torsion spring 16, and the turning member 14, the first fixing member 11 is allowed to turn relative to the adjusting member 13, and to automatically stay in place after being turned by 90 degrees or so. In this manner, the door 18 may be located either at a first position to close the storage space or at a second position to open the storage space and contain an angle of about 90 degrees between the first and the second position.
In connecting the door 18 to the wall surface of the storage space using the hinge 10, it is necessary to adjusting a clearance between the adjusting member 13 and the second fixing member 12, so that the door 18 may be located as close as possible to a horizontal position. The clearance between the adjusting and the second fixing member 13, 12 may be adjusted by turning a second screw 19 designed to push against the adjusting member 13. To increase the clearance between the adjusting member 13 and the second fixing member 12, the second screw 19 must be turned and loosened. Before the second screw 19 can be loosened, it is necessary to slightly loosen the first screw 17. The door hinge 10 illustrated in FIGS. 1 and 2 is one of the commercially available door hinges that has a relatively simple structure and provides relatively low structural strength.
After the door hinge 10 has been used for a period of time, screw holes on the wall surface of the storage space for engaging with the second fixing member 12 would easily become damaged to prevent the door hinge 10 from working normally. Since it is impossible to change the door hinge 10 to another fixing position, a user has no other choice but keeps using the defective door hinge and has a door 18 that could not be operated normally. In other words, a hinged door 18 is often the part of the sectional furniture that gets damaged first.